223 research outputs found

    Comparing methods of barometric efficiency characterisation for specific storage estimation

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    Groundwater responses to barometric pressure fluctuations are characterized using the concept of barometric efficiency (BE). For semiconfined and confined aquifers, BE values can be used to provide efficient, low-cost estimates of specific storage. This study compares, for the first time, eight existing methods of BE estimation. Comparisons were undertaken using data from the Peel region of Western Australia. Fourier analysis and regression deconvolution methods were used to estimate aquifer confinement status. The former approach was found to be robust and provided a quantitative basis for spatial comparisons of the degree of confinement. The latter approach was confounded by the presence of diurnal and/or semidiurnal signals. For wells at which semiconfined or confined responses were identified, frequency and time domain methods were used to estimate BE values. Most BE estimation methods were similarly confounded by diurnal and/or semidiurnal signals, with the exception of the Acworth et al. (2016) method. Specific storage values calculated from BE values were order-of-magnitude consistent with the results of four historical pumping tests. The methods implemented in this research provide efficient, low-cost alternatives to hydraulic testing for estimating aquifer confinement, as well as the BE and specific storage of semiconfined and confined aquifers. The frequency and duration of observations required by these methods are minimal; for example, typically requiring a minimum of four observations per day over a four month period. In some locations they may allow additional insights to be derived from existing groundwater hydrograph data

    Long-term trends in the annual groundwater recharge estimates using the water table fluctuation method

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    Groundwater recharge is critical for sustainable water resource planning and modelling fluid and contaminant transport within th e subsurface. Unfortunately, direct groundwater measurements are often too short to investigate long-term trends for many regions in Australia. Over the past, a number of methods have been developed to estimate groundwater recharge over different temporal and spatial scales. Among the most widely used techniques for estimating recharge, the water table fluctuation (WTF) method has been applied in numerous studies. In this study, we use the WTF method to estimate annual groundwater recharge at 438 groundwater monitoring bores in South Australia and analyse long-term annu al groundwater recharge trends using the nonparametric Mann -Kendall trend test. The results indi cate that the spatially averaged annual groundwater recharge has declined significantly with a trend of -0.92 mm/year for the period 1970- 2012. Similar trend tests for the 237 groundwater monitoring bores with longer data records exhibit that 161 bores have downward trends of which 103 bores are statistically significant, whereas 44 bores have upward trends and 15 of them are statistically significant. Moreover, a linear extrapolation of annual groundwater recharge trend suggests that the m ean will reach the lowest recorded annual recharge in history (2006 drought) by 2058 if the recent clima tic trends continue over a longer peri od, indicating a potential threat to the hydrological and ecological regimes. Furthermor e, the correlation analysis demonstrates that the dominating downward trends in annual groundwater rech arge are affected by the large-scale hydroclimate variables (e.g. rainfall) in South Australia

    Prognostic models for predicting recurrence and survival in women with endometrial cancer

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    This is a protocol for a Cochrane Review (prognosis). The objectives are as follows: To review all prognostic models that combine two or more clinical, histological or molecular variables, or a combination of these variables, to provide an individualised assessment of risk of recurrence or death from disease and evaluate their performance to predict these outcomes in people undergoing curative treatment for endometrial cancer

    Attributing variations of temporal and spatial groundwater recharge: a statistical analysis of climatic and non-climatic factors

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    This paper demonstrated the benefits of statistical methods when investigating the climatic and non-climatic drivers responsible for variations in groundwater recharge with a series of up to 43 years of annual recharge for 426 bores in South-East South Australia. We identified the factors influencing groundwater recharge based on 71 climatic metrics and 13 non-climatic metrics (including groundwater abstraction). The results showed: 1) Rainfall during April to October was the most important variable influencing recharge temporal variation, with its decline identified as the most significant factor related to recharge reduction; 2) In contrast, a negative correlation between rainfall during December to February (DJF) and annual groundwater recharge was found. This suggests that a seasonal shift in rainfall (such as decreasing rainfall during April to October and an increase during DJF) can result in a decline in recharge even when the annual rainfall remains unchanged; 3) The length of wet spells (consecutive rain days) and increasing PET were additional significant predictors for recharge temporal variation. It demonstrated that a simple empirical relationship (such as recharge as a fixed percentage of rainfall) is not a reliable estimation of renewable groundwater resources under changing climatic conditions; 4) There is a statistically significant spatial correlation between mean groundwater depth and recharge, and this implies that a reduction in rainfall can lead to a positive feedback loop of declining recharge and water level; 5) Spatially the most statistically significant factors influencing groundwater recharge were soil types and land attributes. The findings of this study can identify which stressors should be included when investigating the impact of climate change on groundwater recharge

    The Millennium Drought in southeast Australia (2001-2009): Natural and human causes and implications for water resources, ecosystems, economy, and society

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    The "Millennium Drought" (2001-2009) can be described as the worst drought on record for southeast Australia. Adaptation to future severe droughts requires insight into the drivers of the drought and its impacts. These were analyzed using climate, water

    Ambient Observations of Sub-1.0 Hygroscopic Growth Factor and F(RH) Values: Case Studies from Surface and Airborne Measurements

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    This study reports on the first set of ambient observations of sub-1.0 hygroscopicity values (i.e., growth factor, ratio of humidified-to-dry diameter, GF=Dp,wet/Dp,dry and f(RH), ratio of humidified-to-dry scattering coefficients, less than 1) with consistency across different instruments, regions, and platforms. We utilized data from a shipboard humidified tandem differential mobility analyzer (HTDMA) during Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE) in 2011, multiple instruments on the DC-8 aircraft during Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) in 2013, as well as the Differential Aerosol Sizing and Hygroscopicity Spectrometer Probe (DASH-SP) during measurement intensives during Summer 2014 and Winter 2015 in Tucson, Arizona. Sub-1.0 GFs were observed across the range of relative humidity (RH) investigated (75-95%), and did not show a RH-dependent trend in value below 1.0 or frequency of occurrence. A commonality between suppressed hygroscopicity in these experiments, including sub-1.0 GF, was the presence of smoke. Evidence of externally mixed aerosol, and thus multiple GFs, was observed during smoke periods resulting in at least one mode with GF < 1. Time periods during which the DASH-SP detected externally mixed aerosol coincide with sub-1.0 f(RH) observations. Mechanisms responsible for sub-1.0 hygroscopicity are discussed and include refractive index (RI) modifications due to aqueous processing, particle restructuring, and volatilization effects. To further investigate ambient observations of sub-1.0 GFs, f(RH), and particle restructuring, modifying hygroscopicity instruments with pre-humidification modules is recommended

    Factors determining ultra-short-term survival and the commencement of active treatment in high-grade serous ovarian cancer: a case comparison study

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    From Springer Nature via Jisc Publications RouterHistory: received 2020-06-12, accepted 2021-03-10, registration 2021-03-10, pub-electronic 2021-04-08, online 2021-04-08, collection 2021-12Publication status: PublishedFunder: Cancer Research UK; doi: http://dx.doi.org/10.13039/501100000289; Grant(s): 22647Abstract: Background: Despite improvements in median survival some patients with advanced ovarian cancer die within 100 days of diagnosis; the reasons for which remain poorly understood. Here we investigate if ultra short-term survival can be explained by patient characteristics or treatment pathways. Methods: A nested case comparison study was used to examine differences between patients with high grade serous ovarian/fallopian tube cancer who died within 100 days (n = 28) compared to a comparison group of patients matched for histology and including any survival greater than 100 days (n = 134). Results: Cases and comparison patients had similar ages, BMI, ACE-27, deprivation indices, and distribution of disease on CT. There were no significant delays in time to diagnosis or treatment (p = 0.68) between the groups. However, cases had lower serum albumin, haemoglobin and higher platelet counts than matched comparison patients (p < 0.0001) and a worse performance score (P = 0.006). Conclusion: Patients who die rapidly after a diagnosis of ovarian cancer are only slightly older and have similar pre treatment frailty compared to patients whose survival approaches the median. However they do appear to undergo greater physiological compromise as a result of their disease

    The transcriptional repressor bs69 is a conserved target of the e1a proteins from several human adenovirus species

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    Early region 1A (E1A) is the first viral protein produced upon human adenovirus (HAdV) infection. This multifunctional protein transcriptionally activates other HAdV early genes and reprograms gene expression in host cells to support productive infection. E1A functions by interacting with key cellular regulatory proteins through short linear motifs (SLiMs). In this study, the molecular determinants of interaction between E1A and BS69, a cellular repressor that negatively regulates E1A transactivation, were systematically defined by mutagenesis experiments. We found that a minimal sequence comprised of MPNLVPEV, which contains a conserved PXLXP motif and spans residues 112–119 in HAdV-C5 E1A, was necessary and sufficient in binding to the myeloid, Nervy, and DEAF-1 (MYND) domain of BS69. Our study also identified residues P113 and L115 as critical for this interaction. Furthermore, the HAdV-C5 and-A12 E1A proteins from species C and A bound BS69, but those of HAdV-B3,-E4,-D9,-F40, and-G52 from species B, E, D, F, and G, respectively, did not. In addition, BS69 functioned as a repressor of E1A-mediated transactivation, but only for HAdV-C5 and HAdV-A12 E1A. Thus, the PXLXP motif present in a subset of HAdV E1A proteins confers interaction with BS69, which serves as a negative regulator of E1A mediated transcriptional activation
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